Yes, I was aware of the reduction in image quality with the 2x, but can't some of that be made up with higher apertures, such as f11-16? I'm still contemplating the 1.4 which would give me 280mm lens at f4, but with better image quality.

01af:

--- Quote ---If I use a Canon 2X teleconverter on my 70-200/2.8 L will the minimum f-stop at 200mm still be f/5.6?[a href=\"index.php?act=findpost&pid=191805\"][{POST_SNAPBACK}][/a]--- End quote ---No. The minimum f-stop with a 2× TC will be f/64. But the maximum f-stop will be f/5.6 indeed.

--- Quote ---Yes, I was aware of the reduction in image quality with the 2x, but can't some of that be made up with higher apertures, such as f/11-16?[a href=\"index.php?act=findpost&pid=191808\"][{POST_SNAPBACK}][/a]--- End quote ---Yes, it can ... to a degree. But keep in mind that from f/11 on (with APS-C format) or from f/16 on (with 35-mm format) you will start to see diffraction effects. So all in all, you'd be very restricted as far as image quality and choice of apertures goes. Of course, that doesn't mean image quality would be bad or even unusable ... but it would clearly be below the level you're used to from this lens without TC.

--- Quote ---I'm still contemplating the 1.4× which would give me 280 mm lens at f/4, but with better image quality.[a href=\"index.php?act=findpost&pid=191808\"][{POST_SNAPBACK}][/a]--- End quote ---In my opinion, that'd be the wiser choice! You'd sacrifice some telephoto reach in exchange for a better and more versatile lens. The loss of image quality with a 1.4× TC is considerably less than with a 2× TC. If you need the 300 - 400 mm range badly then better buy a lens covering it natively.

-- Olaf

Ken Bennett:
I use the 1.4x on my 70-200 all the time. It's a terrific combo -- still has good focusing speed and excellent sharpness. (Well, excellent for p-j work, handheld fast action stuff, anyway.)